Circuit breaker



y 4 J. G. JACKSON 2,282,520

CIRCUIT BREAKER Filed Aug. 9, 1939 a Sheets-Sheet 1 [N VEN T OR May 12, 1942. -J. GfJACKSON CIRCUIT BREAKER Filed Aug. 9, 1939 3 Sheets-Sheet 2 1 INVENTOR y 1942- J. G. JACKSON 2,282,520

CIRCUIT BREAKER Filed Aug. 9, 1939 3 Sheets-Sheet 5 'llzvn ll 1111111 1N VENTOR Patented May 12, 1942 John G. Jackson, Detroit,

Square D Company, tion of Michigan Micln, assignor to Detroit, Mich., a corpora- Application A ust 9, 1939, Serial No. 289,165

12 Claims.

Thisinvention relates to devices for making and breaking electrical circuits and more particularly to circuit breakers automatically operable in response to a current overload.

One object of the present invention is to provide improved means for the electrical attachment of circuit breakers in a distribution panel.

Another object ofthe present invention is to provide a distribution panel wherein circuit breakers are positioned along a bus bar with a connector disposed between each adjacent pair and connectible to one of the circuit breakers at the side thereof.

Another object of the present invention is to provide individualized covers for each of the circuit breakers, the covers being of suflicient width to span the space between adjacent circuit breakers occasioned by the positioning of bus bar connectors therebetwee'm Other objects and features of the invention will be readily apparent to those skilled in the art from the following specification and appended drawings illustrating the preferred embodiment of the invention in which:

Figure l is a front elevational view of a circuit breaker assembly according to the present invention with certain parts broken away.

Figure 2 is a sectional view taken along the line II-II of Figure 1.

Figure 3 is a fragmentary sectional view taken along the line III-III of Figure 1.

. Figure 4 is a fragmentary sectional view taken-- along the line IV-IV of Figure 1, showing the means for actuating the mounting pan.

Figure 5 is a fragmentary sectional view taken along the line V-V of Figure 3.

Figure 6 is a vertical sectional view of a single circuit breaker mechanism showing the operating parts in overload position.

Figure 7 is a vertical sectional view of the single breaker mechanism showing the parts in a reset position before the contacts are closed.

The automatic electric circuit breaker as herein illustrated and described embodies the main structural and operating features of that described in applicant's Patent No. 2,096,545 entitled Circuit breakers, and the present invention constitutes an improvement or a further development of the invention disclosed therein.

The drawings show two automatic electric circuit breaker units l and 2 (although any number 01' units may be used) adjacently mounted within an enclosing box 3 which has an operable cover I secured thereon as by clamping studs 5. The cover 4 is provided with an opening generally edly mounted upon cover 4 near an edge of the above said opening and is provided with a lock 1 to secure it in closed position. The units l and 2 are of identical construction and, as shown, each comprises an enclosure having a cup-shaped 1 insulating base 8 within which is generally centrally disposed a single piece strap 9 which serves as a contact plate. Said contact plate 9 is formed into a generally U shape having integrally attached thereto ear portions II and- 12. The portion II is disposed on'the outside of the circuit breaker unit extending at right angles to its side wall l3. A stud I4 is threaded into portion II and extend beyond whereby leads from a bus bar may be connected to the circuit breaker unit. Portion I2 is disposed within the circuit breaker unit and bears upon an abutment piece l5 provided upon base 8; and is rigidly secured thereto as by a threaded stud l6, which passes through an opening provided generally centrally of said abutment piece l5. Stationary contact surfaces I! are disposed upon said portion I 2, and, cooperating with said stationary contact surfaces are four individual floating contact bars l8 carrying contact surfaces at one end, and latched at their other ends by bimetallic members I9 adjustably supported on connectors 2| leading to the exterior of the circuit breaker enclosure. Compression springs 22 bias the bars l8 against the stationary contact surfaces l1 and the bimetallic latches IS. The top edges of the bar l8 are provided with pairs of notches 23 and 24 and are received within slots in rectilinearly movable members 26 generally U-shaped in cross section. The longer legs of the elements 26 engage within the notches 23 at the top of the slots. Flexible leads 2.! interconnect the free ends'of the bimetallic latches l9 and intermediate points on the bars I8.

The are chamber adjacent the cooperating contact surfaces may be provided with suitable fibre barriers and openings, but these features form no part of the present invention, and constitute the invention described and claimed in a Patent No. 2,132,627 issued October 11, 193 8 to John G. Jackson.

A fiber sheet 28 is disposed over the top of the base and thereover a cover 29; said cover 29 is formed preferably of steel and is riveted or otherwise sealably secured to the base to prevent access to the circuit breaker parts from the ex- 1 terior. Terminal connectors 3| are provided on ledges at the opposite ends of the exterior of the 2 breaker for the attachment of cable terminal ends thereto.

Pivotally supported as by means of shafts 32 within recesses inthe side walls of base [are operating handles 34 having interior operating portions 35. the top surfaces of the rectilinearly movable elements 26 and constitute cam surfaces which upon rotation move the elements rectilinearly. The operating portions 35 are provided with flat surfaces 36 which form stable supports for the elements 26 in a depressed position corresponding to the manual ofP' breaker mechanism, and with tips 31 for causing a further movement of the elements 26 to reset position or the circuit again close the circuit through the breaker the These interior portions bear against handle is rotated to the normal on position whereupon the parts will assume the position shown at the right in Figure 2.

A mounting plate 42 comprising a central pan shaped portion with inverted U-shaped shoulders 50 disposed at either side of the pan portion the breaker mechanism after an automatic oper- The portions 35 of the operating handles are provided with openings 38 into which project the ends of the spring 39 serving to bias the handles against the members 26. The interior portions 35 of the handles may be provided with cutout portions 4|. to provide for free movement of the springs with relation to the operating portion of the handles.

As seen in Figure 2, the circuit breaker mechanism at the right therein is in the normal on position. When'the handle 34 is rotated to engage the flat surface 36 with the rectilinearly movable member 26, the parts will assume the positions substantially shown at the left in Figure 2, corresponding to manual off position, with the movable contact surface moved to a disengaged position against the bias of the spring 22. This position constitutes a stable position which the parts will retain until the operating handle is moved in reverse direction to permit the movable contact surface to move into engaged position under the bias of the spring 22. The spring 39 in normal "on position of the device shown at the right in Figure 2 biases the handle 34 into engagement with the element 26 and biases this element within the notch 24 in the bar l8. Upon the occurrence of an overload the bimetallic latch is will become heated and move to the position shown in Figure 6, thus unlatching the end of the bar i6 and permitting it to rotate into the position shown in Figure 6. Here the bar is rotated about its engagement with the element 26 and moves the contact to a disengaged position.- The notch 24 is engaged by the shorter leg of the element 26 which serves to limit the rotative movement of the bar, and by its engagement with the notch serves to further insure the proper positioning of the bar with respect to the element 26. As the compression spring 22 is considerably stronger than the light handle spring 39, releasing of the bar l6 from the bimetallic latch I! will rotate the handle 34 beyond the on position against the bias of said light spring 39 into a position indicating the tripped position of the breaker unit.

To reset the mechanism after an automatic operation, the handle is rotated beyond the normal oii." position into that shown in Figure 7, whereupon the tip 31 on the operating portion 35 of the handle engages the element 26 and forces it into the position shown. In this rotation of the handle the contact end of the bar l8 engages the bottom of the arc chamber and causes the bar to rotate about its engagement with the member 26 into the position shown. When the handle is released from the position in Figure 'l, the parts will assume the position of normal oil as shown at the left in Figure 2A To cuit breaker unit the stud l4 carried by the exterior portion ll of and adapted to support a circuit breaker assembly thereover is secured to the base of box 3 as by studs 43 and cooperating locking nuts 44.

Studs 45 are provided at each comer of the plate 42 having a threaded engagement therewith for properly positioning the circuit breaker assembly with respect to the cover 4. Rotation of the studs 45 will cause'the mounting plate 42 to rise upwardly forcing the circuit breaker assembly fthereon up against a pan shaped trim 46 rigidly secured upon cover 4 and extending downwardly into the interior of the box 3. 'With the circuit breaker assembly properly positioned, the looking nuts 44 are then rotated into engagement with themounting pan 42 to rigidly secure the latter in this position.

An insulating sheet 41 is disposed substantially throughout the central pan portion of the mounting plate 42. Insulated blocks 48 and 46 are disposed thereover crosswise within said pan portion and at either end and are secured in place as by button head studs 5|. 'Upon said blocks are mounted bus bars 52, being secured thereto by studs 53; Said bus bars 52 extend longitudinally along the plate 42 and are of substantially the same length as the circuit breaker assembly to be disposed thereabove. Lugs 54 are provided at the lower ends of the bus bars 52 to accommodate line wires to be attached thereto. Upon the inverted U-shaped shoulders 50 of the mounting plate 42 are mounted flanged bearing pieces 55 being rigidly secured thereto as by studs 56. The circuit breaker units l and '2 are mounted in place by means of studs 51 which pass through diagonally opposite openings in the units and are threaded into the bearing pieces 55. To lessen the possibility of a short circuit, insulating strips 58 are disposed between the bus bars 52 and the bearing pieces 55.

The circuit breaker units are mounted upon the bearing pieces 55 a suflicient distance apart from eachother to permit the disposition therebetween 01' a conducting strap 59. The conducting strap 56 is of generally Z-shape and is provided with legs 6| and 62. Leg 6| is adapted to be fastened to the bus bar 52 as by a stud 63.

Leg 62 extending inwardly alongside of the cir- I5 is secured thereto through the contact piece 9. The conducting straps 53 are to be disposed so that alternate conducting straps are connected to the same bus bar.

Each circuit breaker unit is provided with an individualized cover 64. Said cover is of greater width than the unit in order that it may sparn the space made by the disposing of the conducting straps 59 alongside each unit and may touch the cover of the adjoining circuit breaker unit and thus form a solid front and thereby prevent accidental contact with the live portions enclosed therebeneath. The covers are secured to v the circuit breaker unit by the same studs 51 which mount the units in place upon the bearing pieces 55.

Generally U-shaped housings 65 are disposed at either end of the circuit breaker assembly, the upper housing being disposed about a neuaaeasao,

tral terminal plate not shown, and the. lower housing being disposed about the lugs 48 provided at the lower ends of the bus bar I52 for connec-- tion of the line wires. The disposing of the housings 65 in this manner extends the solid front presented by the individualized covers 64 and makes it very diflicult to come into accidental contact with any of the live parts of the panel board.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of vthe following claims.

What is claimed is:

1. In a circuit breaker panelboard, a plurality,

of horizontally spaced bus bars, a plurality of automatic electric circuit breaker units mounted directly in front of said bus bars in superposed relation and with their longitudinal axes transverse to the bus bars, each of said units including a sealed enclosure for the circuit breaker mechanism preventing access thereto, conducting means connected to the circuit breaker mechanism within the enclosure and extending to the exterior thereof at a side of each of the units parallel to its longitudinal axis, and means for conductively connecting said conducting means to a bus bar, said connecting means being readily manipulable at the side of a circuit breaker unit while the unit is in place in the panelboard in front of the bus bar.

2. In a circuit breaker panelboard, a plurality of bus bars, a plurality of automatic electric circuit breaker units mounted directly in front of said bus bars in superposed relation and with their longitudinal axes transverse to the bus bars, each of said units including a sealed enclosure for the circuit breaker mechanism preventing access thereto, conducting means connected to the circuit breaker mechanism within the enclosure and extending to a side of each of the units parallel to its longitudinalaxis, conducting means 4. In a circuit breaker panelboard, a plurality of horizontally spaced bus bars, a plurality of automatic electric circuit breaker mechanisms mounted directly in front of said bus bars in superposed relation, each of said units including a sealed enclosure for'the circuit breaker mechanism preventing access thereto, said units being spaced longitudinally of the bus bars, conducting means on the units extending into said spaces between the units, conductingmeans connected to the bus bar and also extending into the spaces between the units, and means for interconnecting said conducting means, said connecting means being readily accessible for manipulation in the spaces between said units while the units are positioned in the. panelboard in front of the bus bars. s

,5. A circuit breaker panelboard comprising a plurality of spaced bus bars, a plurality of automatic electric circuit breaker units disposed directly in front of said bus bars in superposed relation, each of said units including a sealed enclosure for the circuit breaker mechanism preventing access thereto, said units being spaced conductively secured to a bus bar and extending at the samesides of the circuit breaker units into positions adjacent to the ends of said first mentioned conducting means, and means for conductively connecting said conducting means, said connecting means being readily manipulable at said sides of the circuit breaker units while they are in assembled position in the panelboard in front of the bus bars.

3. In a circuit breaker panelboard, a plurality of horizontally spaced bus bars, a plurality of automatic electric circuit breaker units mounted directly in front of said bus bars in superposed relation, said units having their longitudinal axes transverse to the bus bars and being mounted in spaced relation longitudinally of the bus bars, said units including sealed enclosures for the circuit breaker mechanism to prevent access thereto, conducting means connected to the circuit breaker mechanism within the enclosure and extending into the spaces between the units, conducting means connected to the bus bars and also extending into the spaces between the units, and means for interconnecting said conducting means within the spaces between the units, said connecting means being readily accessible for manipulation within said spaces while the units are assembled in position in the panelboardxin front of the bus bars.

nratic electric circuit .of the unit will longitudinally of the bus bars, conducting means on said units at substantially the central portions thereof extending into the spaces between the units and means in the spaces between the units for connecting said conducting means to the bus bars, said connecting means being readily accessible for manipulation in the spaces between the units, while the units are positioned in the panelboard in front of the bus bars.

6. A circuit breaker panelboard comprising a plurality of spaced bus bars, a plurality of automatic electric-circuit breaker units disposed directly in front of said bus bars in superposed relation, each of said units including a sealed enclosure for the circuit breaker mechanism preventing access thereto, said units being spaced longitudinally of the bus bars, bus tap means electrically connected to the mechanisms within the enclosures and extending from the units into the spaces therebetween, bussing straps connected to the bus bars and also extending into spaces between the units into engagement with said bus taps, and means in the spaces between the units for interconnecting said bus taps and bussing straps to connect the circuit breaker mechanisms to the bus bars, said connecting means being readily accessible for manipulation in the spaces between the units, while the units are positioned in the panelboard in front of the bus bars.

7. A circuit breaker panelboard comprising a plurality of spaced bus bars, a plurality of autobreaker units disposed directly in front of said bus bars in superposed relation, each of said units including a sealed enclosure for the circuit breaker mechanism preventing access thereto, said units being spaced longitudinally of the bus bars, bus tap means electrically connected to the mechanisms within the enclosures and extending from the units into the spaces therebetween, all of said bus tap means of the same polarity being directed in the same direction in the panelboard so that the body be interposed betwen bus tap means of different polarity, bussing straps connected to the bus bars and also extending into spaces between the units into engagement with said bus taps, and means in the spaces between the units for interconnecting said bus taps and bussing straps to connect the circuit breaker mechanisms to the bus bars, said connecting means being readily accessible for manipulation in the spaces between the units, while the units are positioned in the panelboard in front of the bus bars.

8. A circuit breaker panelboard comprising a plurality of spaced bus bars. a plurality of conducting straps connected to said bus .bars at longitudinally spaced points thereon and extending forwardly thereof, a plurality of automatic electric circuit breaker units mounted directly over said bus bars and in the spaces between said straps whereby the forward portions of the straps extend into the spaces between the units, said units including sealed enclosures for the circuit breaker mechanisms preventing access thereto, bus tap means electrically connected to the circuit breaker mechanisms and extending into the spaces between the units, and means interconnecting said bus tap means and the conducting straps of the busses, said connecting means being readily accessible for manipulation in the spaces between the units, while the units are positioned in the panelboard in front of the bus bars.

9. In a circuit breaker panelboard, a plurality of spaced bus bars, a plurality of automatic electric circuit breaker units mounted directly in front of said bus bars, said units being spaced longitudinally of the bus bars, means within the spades between the units for electrically connecting the units to the bus bars, and individual cover means' for each of said circuit breaker units, said covers being of suflicient width and being so disposed as to span both a unit and one of the spaces therebeside, whereby removal of a cover from a unit will render a space adjacent to the unit open for access and manipulation of the connecting means.

10. A circuit breaker panelboard comprising a plurality of spaced bus bars, a plurality of automatic electric circuit breaker units mounted directly in front of said bus bars, said .units being .spaced apart longitudinally of the bus bars,

bussing straps connected to the bus bars and extending into the spaces between the units, bus tap means extending from each oft the units into the spaces therebetween, means in said spaces for connecting the bus tap means to the bussing straps, and individual covers for said circuit breaker units, said covers being of sufficient width and being so disposed as to cover both a unit and the entire space adjacent thereto, whereby removal'of a cover from a unit fully exposes a space adjacent thereto for access and manipulation of the connecting means therein.

11. A circuit breaker panelboard comprising a plurality of spaced bus bars, a plurality of circuit breaker units mounted directly in front of said bus bars, said units being spaced apart longitudinally of the bus bars, means for connecting said units to the bus bars, the spaces between said units providing access to said connecting means, and individual covers for said units, said covers being of sufiicient width and being so disposed as to span both a unit and a space adjacent thereto, whereby removal of the cover from a unit will fully expose the space adjacent thereto for access to said connecting means.

12. A circuit breaker panelboard comprising a plurality of spaced bus bars, a plurality of circuit breaker units mounted directly in front of said bus bars, said units including sealed enclosures for the circuit breaker mechanism preventing access thereto, said units being spaced longitudinally of the bus bars, bus tap means electrically connected to said circuit breaker mechanisms and extending into the spaces between the units, bussing straps connected to the bus bars and extending into spaces between the units, means in the spaces between the units for connecting the bus tap means to the bussing straps to electrically connect the circuit breaker mechanisms to the bus bars, and individual covers for said circuit breaker units, said covers being of suflicient width and being so disposed as to span both a unit and a space adjacent thereto, whereby removal of a cover from a unit will fully expose a space adjacent thereto for ready access to said connecting means.

JOHN G. JACKSON. 

